Quilting Calculator

Quilt Size Calculator

Calculate finished quilt dimensions from a block layout, plan a target size from a mattress or check whether an existing quilt meets your bed-coverage target.

Quilting fabric for finished quilt size planning

Finished quilt dimensions

Enter your quilt measurements

Calculate size from a block layout

Use finished block, sashing and border measurements.

Finished block width in Finished block height in Blocks across Blocks down Finished sashing width in Between blocks only. Finished border width in Applied to all four outer edges.

Finished dimensions

Your quilt size

Quilting fabric for planning finished quilt dimensions

Finished quilt size — Press Calculate Quilt Size

Width—

Length—

Area—

Blocks / Fit—

Calculation details

Detail A—

Detail B—

Detail C—

Detail D—

Calculation details appear here.

Quilt layout

Visual size plan

Enter your measurements

Press Calculate Quilt Size to build the layout plan.

Across—

Down—

Finished width—

Finished length—

Calculation summary

Your measurements

Quilt size—

Layout / mattress—

Sashing / side drop—

Border / foot drop—

Units—

Block layout math

Combine rows, columns, sashing and borders into one finished size.

Bed drop planning

Set side drop, foot drop and optional pillow tuck from mattress dimensions.

Fit check

Compare a planned quilt with the coverage target before changing the layout.

Two unit systems

Work in inches or centimeters to match the measurements in your project.

How to Calculate Finished Quilt Size

Finished quilt size depends on the number of blocks across and down, the finished dimensions of those blocks, sashing between the blocks and borders around the outside.

Quilt Size Formula for a Block Layout

Finished width(block width × columns) + (sashing × (columns − 1)) + (2 × border)

Finished length(block height × rows) + (sashing × (rows − 1)) + (2 × border)

Worked Example: 5 × 6 Quilt Layout

Five 12-inch blocks across and six 12-inch blocks down, with 2-inch finished sashing between blocks and a 4-inch outer border, produce a finished quilt top measuring 76 × 90 inches.

Calculate Quilt Size for a Bed

Add the desired drop to both sides of the mattress for quilt width. For length, add the foot drop and any optional pillow tuck to the mattress length.

Target widthmattress width + (2 × side drop)

Target lengthmattress length + foot drop + pillow tuck

Finished Size vs. Cut Size

Block Layout mode expects finished block and sashing measurements. Finished size is what each piece contributes after seam allowances are sewn.

Quilt Size Calculator FAQ

How do I calculate quilt size from blocks?

Multiply finished block width by columns and finished block height by rows, then add sashing between blocks and borders around the outside.

How many sashing spaces are in a row?

If sashing is only between blocks, five blocks have four sashing spaces between them.

How much does a border add?

A 4-inch finished border adds 8 inches to quilt width and 8 inches to quilt length.

Should I use cut or finished block size?

Use finished block size because the result represents the assembled quilt top.

Does this calculate backing or batting?

No. Those materials have separate calculators because they use different allowances and inputs.

Related Quilt Calculators

Continue with the Quilt Backing Calculator, Quilt Batting Calculator, Quilt Binding Calculator or Quilt Block Calculator.